Kong Y, Han M, Lee M, et al. - This study was sought to explore whether and how calcium and vitamin D use are associated with the revision rate after primary total knee arthroplasty. Researchers performed a nationwide population-based cohort study applying the Korean National Health Insurance database. Between 2009 and 2018, researchers enrolled individuals diagnosed with knee osteoarthritis and had undergone primary total knee arthroplasty. They calculated risk for arthroplasty revision applying a Cox proportional hazards model with time-dependent covariates. The survival of knee arthroplasty was evaluated by using log-rank test. A total of 142,147 individuals were included in the study. It was shown that after total knee arthroplasty, combination use of calcium and vitamin D with a dose of 800 IU or greater for more than 1 year was correlated with the greatest reduction in the risks for revision surgery.